Sharpening Blades - Jacobsen R-311T Maintenance Manual

4 MAINTENANCE
4.3

SHARPENING BLADES_____________________________________________________

1. Place a wooden block between the blade and mower
housing to stop the blade from moving. To remove
blade, turn screw holding blade counterclockwise
!
WARNING
The mower blades can develop sharp edges. Use
caution whenever servicing and handling.
2. When dressing or sharpening the blade, do not
follow the original pattern of grind as shown in (A).
Grind new cutting edges at an angle as shown in
(B).
If the maximum total loss of the blade reaches 1/2 in.
(13 mm), do not sharpen further, replace blade.
!
WARNING
Resharpening the blade beyond the allowable 1/2 in.
(13 mm) may allow blade tip to break off and be
thrown from the mower. Such an incident can cause
very serious injury to bystanders and/or property
damage.
3. Make sure an equal amount of material is removed
from both sides of blade to prevent having an
unbalanced blade. An unbalanced blade will cause
excessive vibration and may damage the mower.
4. Use a blade balancer (JAC 5016) to check the blade
after sharpening.
5. Identify the three clockwise rotation (D) and four
counter-clockwise rotation (E) blades. The blades for
clockwise rotation are installed on the left front deck
motor, the outside left wing deck motor, and the
inside right wing
determined by normal motor rotation viewed from
top of deck).
6. Install blades so cutting edges (C) face the direction
of rotation as shown in Figure 4C. Air vane of blade
must face in toward deck housing.
Torque center mounting screw holding blade to 75 ft.
lb. (102 Nm).
20
deck motor. (Rotation
.
Bottom view of front deck
is
raised to their transport position.
A
Maximum
1/2" (13 mm)
B
C
C
C
E
E
D
in its service position
C
D
E
Left Side
C
E
D
Right Side
Bottom view of side decks
HR024
Figure 4B
Figure 4C